1. Field of the Invention
The present invention generally relates to voltage regulator modules (or VRMs) for regulating voltage provided to microprocessors and, more particularly an integrated non-isolated VRM and microprocessor assembly.
2. Related Art
A voltage regulator module or VRM, sometimes called PPM (power processing module) is an electronic device that provides a microprocessor the appropriate supply voltage. It can be soldered to the motherboard or be an installable device. It allows processors with different supply voltage to be mounted on the same motherboard. (A motherboard is the central or primary circuit board making up a complex electronic system, such as a modern computer. It is also known as a mainboard, baseboard, system board, or, on Apple® computers, a logic board.)
Some voltage regulators provide a fixed supply voltage to the processor, but most of them sense the required supply voltage from the processor. In particular, VRMs that are soldered to the motherboard are supposed to do the sensing.
The correct supply voltage is communicated by the microprocessor to the VRM at startup via a number of bits called VID (voltage identifier). In particular, the VRM initially provides a standard supply voltage to the VID logic, which is the part of the processor whose only aim is to then send the VID to the VRM. When the VRM has received the VID identifying the required supply voltage, it starts acting as a voltage regulator, providing the required constant voltage supply to the processor.
However, because systems of the prior art utilize a discrete assembly which uses a discrete controller, inductors, capacitors, and MOSFETs, the DC-DC regulation is not reliable. (The metal-oxide-semiconductor field-effect transistor (MOSFET, MOS-FET, or MOS FET) is by far the most common field-effect transistor in both digital and analog circuits.) Because of the unreliability of the discrete assembly, redundant VRMs are required for availability. In addition, discrete assemblies require a lot of motherboard space.
FIG. 1 illustrates a discrete assembly 100 of the prior art. As discussed above, the discrete assembly on motherboard 101 comprises discrete components such as discrete controller 102, inductors L1 104, capacitors C1, C2 106, and MOSFETs Q1, Q2 108.
Another problem of the prior art is the expense of a discrete connector and VRM to power the microprocessor. Further drawbacks of the known solutions include the large size, thermal issues and reliability of the VRM.
Therefore, there exists a need for a solution that solves at least one of the deficiencies of the related art.